sandbox/seccomp: rename flag type and constants

The names are ambiguous. Rename them to make more sense.

Signed-off-by: Ophestra <cat@gensokyo.uk>

cmd/fpkg/app.go

@@ -111,10 +111,10 @@ func (app *appInfo) toFst(pathSet *appPathSet, argv []string, flagDropShell bool
 		},
 	}
 	if app.Multiarch {
-		config.Confinement.Sandbox.Seccomp |= seccomp.FlagMultiarch
+		config.Confinement.Sandbox.Seccomp |= seccomp.FilterMultiarch
 	}
 	if app.Bluetooth {
-		config.Confinement.Sandbox.Seccomp |= seccomp.FlagBluetooth
+		config.Confinement.Sandbox.Seccomp |= seccomp.FilterBluetooth
 	}
 	return config
 }

cmd/fpkg/with.go

@@ -39,7 +39,7 @@ func withNixDaemon(
 				Hostname: formatHostname(app.Name) + "-" + action,
 				Userns:   true, // nix sandbox requires userns
 				Net:      net,
-				Seccomp:  seccomp.FlagMultiarch,
+				Seccomp:  seccomp.FilterMultiarch,
 				Tty:      dropShell,
 				Filesystem: []*fst.FilesystemConfig{
 					{Src: pathSet.nixPath, Dst: "/nix", Write: true, Must: true},
@@ -76,7 +76,7 @@ func withCacheDir(
 			Shell:    shellPath,
 			Sandbox: &fst.SandboxConfig{
 				Hostname: formatHostname(app.Name) + "-" + action,
-				Seccomp:  seccomp.FlagMultiarch,
+				Seccomp:  seccomp.FilterMultiarch,
 				Tty:      dropShell,
 				Filesystem: []*fst.FilesystemConfig{
 					{Src: path.Join(workDir, "nix"), Dst: "/nix", Must: true},

dbus/proc.go

@@ -63,7 +63,7 @@ func (p *Proxy) Start(ctx context.Context, output io.Writer, useSandbox bool) er
 			c, toolPath,
 			p.seal, true,
 			argF, func(container *sandbox.Container) {
-				container.Seccomp |= seccomp.FlagMultiarch
+				container.Seccomp |= seccomp.FilterMultiarch
 				container.Hostname = "fortify-dbus"
 				container.CommandContext = p.CommandContext
 				if output != nil {

fst/config.go

@@ -106,7 +106,7 @@ func Template() *Config {
 				Userns:        true,
 				Net:           true,
 				Dev:           true,
-				Seccomp:       seccomp.FlagMultiarch,
+				Seccomp:       seccomp.FilterMultiarch,
 				Tty:           true,
 				Multiarch:     true,
 				MapRealUID:    true,

fst/sandbox.go

@@ -21,7 +21,7 @@ type (
 		Hostname string `json:"hostname,omitempty"`
 
 		// extra seccomp flags
-		Seccomp seccomp.SyscallOpts `json:"seccomp"`
+		Seccomp seccomp.FilterOpts `json:"seccomp"`
 		// allow ptrace and friends
 		Devel bool `json:"devel,omitempty"`
 		// allow userns creation in container
@@ -98,7 +98,7 @@ func (s *SandboxConfig) ToContainer(sys SandboxSys, uid, gid *int) (*sandbox.Par
 	}
 
 	if s.Multiarch {
-		container.Seccomp |= seccomp.FlagMultiarch
+		container.Seccomp |= seccomp.FilterMultiarch
 	}
 
 	/* this is only 4 KiB of memory on a 64-bit system,

internal/app/shim.go

@@ -163,9 +163,7 @@ func ShimMain() {
 		fmsg.PrintBaseError(err, "cannot configure container:")
 	}
 
-	if err := seccomp.Load(seccomp.FlagExt |
+	if err := seccomp.Load(seccomp.PresetCommon); err != nil {
-		seccomp.FlagDenyNS | seccomp.FlagDenyTTY | seccomp.FlagDenyDevel |
-		seccomp.FlagMultiarch); err != nil {
 		log.Fatalf("cannot load syscall filter: %v", err)
 	}
 

sandbox/container.go

@@ -27,18 +27,18 @@ const (
 	FAllowNet
 )
 
-func (flags HardeningFlags) seccomp(opts seccomp.SyscallOpts) seccomp.SyscallOpts {
+func (flags HardeningFlags) seccomp(opts seccomp.FilterOpts) seccomp.FilterOpts {
 	if flags&FSyscallCompat == 0 {
-		opts |= seccomp.FlagExt
+		opts |= seccomp.FilterExt
 	}
 	if flags&FAllowDevel == 0 {
-		opts |= seccomp.FlagDenyDevel
+		opts |= seccomp.FilterDenyDevel
 	}
 	if flags&FAllowUserns == 0 {
-		opts |= seccomp.FlagDenyNS
+		opts |= seccomp.FilterDenyNS
 	}
 	if flags&FAllowTTY == 0 {
-		opts |= seccomp.FlagDenyTTY
+		opts |= seccomp.FilterDenyTTY
 	}
 	return opts
 }
@@ -95,7 +95,7 @@ type (
 		// Sequential container setup ops.
 		*Ops
 		// Extra seccomp options.
-		Seccomp seccomp.SyscallOpts
+		Seccomp seccomp.FilterOpts
 		// Permission bits of newly created parent directories.
 		// The zero value is interpreted as 0755.
 		ParentPerm os.FileMode

sandbox/container_test.go

@@ -164,7 +164,7 @@ func e(root, target, vfsOptstr, fsType, source, fsOptstr string) *vfs.MountInfoE
 func TestContainerString(t *testing.T) {
 	container := sandbox.New(context.TODO(), "ldd", "/usr/bin/env")
 	container.Flags |= sandbox.FAllowDevel
-	container.Seccomp |= seccomp.FlagMultiarch
+	container.Seccomp |= seccomp.FilterMultiarch
 	want := `argv: ["ldd" "/usr/bin/env"], flags: 0x2, seccomp: 0x2e`
 	if got := container.String(); got != want {
 		t.Errorf("String: %s, want %s", got, want)

sandbox/seccomp/api.go

@@ -8,11 +8,16 @@ import (
 	"git.gensokyo.uk/security/fortify/helper/proc"
 )
 
+const (
+	PresetStrict = FilterExt | FilterDenyNS | FilterDenyTTY | FilterDenyDevel
+	PresetCommon = PresetStrict | FilterMultiarch
+)
+
 // New returns an inactive Encoder instance.
-func New(opts SyscallOpts) *Encoder { return &Encoder{newExporter(opts)} }
+func New(opts FilterOpts) *Encoder { return &Encoder{newExporter(opts)} }
 
 // Load loads a filter into the kernel.
-func Load(opts SyscallOpts) error { return buildFilter(-1, opts) }
+func Load(opts FilterOpts) error { return buildFilter(-1, opts) }
 
 /*
 An Encoder writes a BPF program to an output stream.
@@ -42,11 +47,11 @@ func (e *Encoder) Close() error {
 }
 
 // NewFile returns an instance of exporter implementing [proc.File].
-func NewFile(opts SyscallOpts) proc.File { return &File{opts: opts} }
+func NewFile(opts FilterOpts) proc.File { return &File{opts: opts} }
 
 // File implements [proc.File] and provides access to the read end of exporter pipe.
 type File struct {
-	opts SyscallOpts
+	opts FilterOpts
 	proc.BaseFile
 }
 

sandbox/seccomp/export.go

@@ -7,7 +7,7 @@ import (
 )
 
 type exporter struct {
-	opts SyscallOpts
+	opts FilterOpts
 	r, w *os.File
 
 	prepareOnce sync.Once
@@ -53,6 +53,6 @@ func (e *exporter) closeWrite() error {
 	return e.closeErr
 }
 
-func newExporter(opts SyscallOpts) *exporter {
+func newExporter(opts FilterOpts) *exporter {
 	return &exporter{opts: opts}
 }

sandbox/seccomp/export_test.go

@@ -14,7 +14,7 @@ import (
 func TestExport(t *testing.T) {
 	testCases := []struct {
 		name    string
-		opts    seccomp.SyscallOpts
+		opts    seccomp.FilterOpts
 		want    []byte
 		wantErr bool
 	}{
@@ -28,7 +28,7 @@ func TestExport(t *testing.T) {
 			0xa7, 0x9b, 0x07, 0x0e, 0x04, 0xc0, 0xee, 0x9a,
 			0xcd, 0xf5, 0x8f, 0x55, 0xcf, 0xa8, 0x15, 0xa5,
 		}, false},
-		{"base", seccomp.FlagExt, []byte{
+		{"base", seccomp.FilterExt, []byte{
 			0xdc, 0x7f, 0x2e, 0x1c, 0x5e, 0x82, 0x9b, 0x79,
 			0xeb, 0xb7, 0xef, 0xc7, 0x59, 0x15, 0x0f, 0x54,
 			0xa8, 0x3a, 0x75, 0xc8, 0xdf, 0x6f, 0xee, 0x4d,
@@ -38,10 +38,10 @@ func TestExport(t *testing.T) {
 			0x1d, 0xb0, 0x5d, 0x90, 0x99, 0x7c, 0x86, 0x59,
 			0xb9, 0x58, 0x91, 0x20, 0x6a, 0xc9, 0x95, 0x2d,
 		}, false},
-		{"everything", seccomp.FlagExt |
+		{"everything", seccomp.FilterExt |
-			seccomp.FlagDenyNS | seccomp.FlagDenyTTY | seccomp.FlagDenyDevel |
+			seccomp.FilterDenyNS | seccomp.FilterDenyTTY | seccomp.FilterDenyDevel |
-			seccomp.FlagMultiarch | seccomp.FlagLinux32 | seccomp.FlagCan |
+			seccomp.FilterMultiarch | seccomp.FilterLinux32 | seccomp.FilterCan |
-			seccomp.FlagBluetooth, []byte{
+			seccomp.FilterBluetooth, []byte{
 			0xe9, 0x9d, 0xd3, 0x45, 0xe1, 0x95, 0x41, 0x34,
 			0x73, 0xd3, 0xcb, 0xee, 0x07, 0xb4, 0xed, 0x57,
 			0xb9, 0x08, 0xbf, 0xa8, 0x9e, 0xa2, 0x07, 0x2f,
@@ -51,8 +51,7 @@ func TestExport(t *testing.T) {
 			0x4c, 0x02, 0x4e, 0xd4, 0x88, 0x50, 0xbe, 0x69,
 			0xb6, 0x8a, 0x9a, 0x4c, 0x5f, 0x53, 0xa9, 0xdb,
 		}, false},
-		{"strict", seccomp.FlagExt |
+		{"strict", seccomp.PresetStrict, []byte{
-			seccomp.FlagDenyNS | seccomp.FlagDenyTTY | seccomp.FlagDenyDevel, []byte{
 			0xe8, 0x80, 0x29, 0x8d, 0xf2, 0xbd, 0x67, 0x51,
 			0xd0, 0x04, 0x0f, 0xc2, 0x1b, 0xc0, 0xed, 0x4c,
 			0x00, 0xf9, 0x5d, 0xc0, 0xd7, 0xba, 0x50, 0x6c,
@@ -63,7 +62,7 @@ func TestExport(t *testing.T) {
 			0x14, 0x89, 0x60, 0xfb, 0xd3, 0x5c, 0xd7, 0x35,
 		}, false},
 		{"strict compat", 0 |
-			seccomp.FlagDenyNS | seccomp.FlagDenyTTY | seccomp.FlagDenyDevel, []byte{
+			seccomp.FilterDenyNS | seccomp.FilterDenyTTY | seccomp.FilterDenyDevel, []byte{
 			0x39, 0x87, 0x1b, 0x93, 0xff, 0xaf, 0xc8, 0xb9,
 			0x79, 0xfc, 0xed, 0xc0, 0xb0, 0xc3, 0x7b, 0x9e,
 			0x03, 0x92, 0x2f, 0x5b, 0x02, 0x74, 0x8d, 0xc5,
@@ -73,7 +72,7 @@ func TestExport(t *testing.T) {
 			0x80, 0x8b, 0x1a, 0x6f, 0x84, 0xf3, 0x2b, 0xbd,
 			0xe1, 0xaa, 0x02, 0xae, 0x30, 0xee, 0xdc, 0xfa,
 		}, false},
-		{"fortify default", seccomp.FlagExt | seccomp.FlagDenyDevel, []byte{
+		{"fortify default", seccomp.FilterExt | seccomp.FilterDenyDevel, []byte{
 			0xc6, 0x98, 0xb0, 0x81, 0xff, 0x95, 0x7a, 0xfe,
 			0x17, 0xa6, 0xd9, 0x43, 0x74, 0x53, 0x7d, 0x37,
 			0xf2, 0xa6, 0x3f, 0x6f, 0x9d, 0xd7, 0x5d, 0xa7,
@@ -138,10 +137,10 @@ func TestExport(t *testing.T) {
 func BenchmarkExport(b *testing.B) {
 	buf := make([]byte, 8)
 	for i := 0; i < b.N; i++ {
-		e := seccomp.New(seccomp.FlagExt |
+		e := seccomp.New(seccomp.FilterExt |
-			seccomp.FlagDenyNS | seccomp.FlagDenyTTY | seccomp.FlagDenyDevel |
+			seccomp.FilterDenyNS | seccomp.FilterDenyTTY | seccomp.FilterDenyDevel |
-			seccomp.FlagMultiarch | seccomp.FlagLinux32 | seccomp.FlagCan |
+			seccomp.FilterMultiarch | seccomp.FilterLinux32 | seccomp.FilterCan |
-			seccomp.FlagBluetooth)
+			seccomp.FilterBluetooth)
 		if _, err := io.CopyBuffer(io.Discard, e, buf); err != nil {
 			b.Fatalf("cannot export: %v", err)
 		}

sandbox/seccomp/seccomp-build.c

@@ -47,7 +47,7 @@ struct f_syscall_act {
   }                                                                                                               \
 } while (0)
 
-int32_t f_build_filter(int *ret_p, int fd, uint32_t arch, uint32_t multiarch, f_syscall_opts opts) {
+int32_t f_build_filter(int *ret_p, int fd, uint32_t arch, uint32_t multiarch, f_filter_opts opts) {
   int32_t res = 0; // refer to resErr for meaning
   int allow_multiarch = opts & F_MULTIARCH;
   int allowed_personality = PER_LINUX;
@@ -209,7 +209,7 @@ int32_t f_build_filter(int *ret_p, int fd, uint32_t arch, uint32_t multiarch, f_
   struct
   {
     int            family;
-    f_syscall_opts flags_mask;
+    f_filter_opts flags_mask;
   } socket_family_allowlist[] = {
     // NOTE: Keep in numerical order
     { AF_UNSPEC, 0 },

sandbox/seccomp/seccomp-build.h

@@ -17,7 +17,7 @@ typedef enum {
   F_LINUX32    = 1 << 6,
   F_CAN        = 1 << 7,
   F_BLUETOOTH  = 1 << 8,
-} f_syscall_opts;
+} f_filter_opts;
 
 extern void f_println(char *v);
-int32_t f_build_filter(int *ret_p, int fd, uint32_t arch, uint32_t multiarch, f_syscall_opts opts);
+int32_t f_build_filter(int *ret_p, int fd, uint32_t arch, uint32_t multiarch, f_filter_opts opts);

sandbox/seccomp/seccomp.go

@@ -57,29 +57,29 @@ var resPrefix = [...]string{
 	7: "seccomp_load failed",
 }
 
-type SyscallOpts = C.f_syscall_opts
+type FilterOpts = C.f_filter_opts
 
 const (
-	flagVerbose SyscallOpts = C.F_VERBOSE
+	filterVerbose FilterOpts = C.F_VERBOSE
-	// FlagExt are project-specific extensions.
+	// FilterExt are project-specific extensions.
-	FlagExt SyscallOpts = C.F_EXT
+	FilterExt FilterOpts = C.F_EXT
-	// FlagDenyNS denies namespace setup syscalls.
+	// FilterDenyNS denies namespace setup syscalls.
-	FlagDenyNS SyscallOpts = C.F_DENY_NS
+	FilterDenyNS FilterOpts = C.F_DENY_NS
-	// FlagDenyTTY denies faking input.
+	// FilterDenyTTY denies faking input.
-	FlagDenyTTY SyscallOpts = C.F_DENY_TTY
+	FilterDenyTTY FilterOpts = C.F_DENY_TTY
-	// FlagDenyDevel denies development-related syscalls.
+	// FilterDenyDevel denies development-related syscalls.
-	FlagDenyDevel SyscallOpts = C.F_DENY_DEVEL
+	FilterDenyDevel FilterOpts = C.F_DENY_DEVEL
-	// FlagMultiarch allows multiarch/emulation.
+	// FilterMultiarch allows multiarch/emulation.
-	FlagMultiarch SyscallOpts = C.F_MULTIARCH
+	FilterMultiarch FilterOpts = C.F_MULTIARCH
-	// FlagLinux32 sets PER_LINUX32.
+	// FilterLinux32 sets PER_LINUX32.
-	FlagLinux32 SyscallOpts = C.F_LINUX32
+	FilterLinux32 FilterOpts = C.F_LINUX32
-	// FlagCan allows AF_CAN.
+	// FilterCan allows AF_CAN.
-	FlagCan SyscallOpts = C.F_CAN
+	FilterCan FilterOpts = C.F_CAN
-	// FlagBluetooth allows AF_BLUETOOTH.
+	// FilterBluetooth allows AF_BLUETOOTH.
-	FlagBluetooth SyscallOpts = C.F_BLUETOOTH
+	FilterBluetooth FilterOpts = C.F_BLUETOOTH
 )
 
-func buildFilter(fd int, opts SyscallOpts) error {
+func buildFilter(fd int, opts FilterOpts) error {
 	var (
 		arch      C.uint32_t = 0
 		multiarch C.uint32_t = 0
@@ -100,7 +100,7 @@ func buildFilter(fd int, opts SyscallOpts) error {
 	// this removes repeated transitions between C and Go execution
 	// when producing log output via F_println and CPrintln is nil
 	if fp := printlnP.Load(); fp != nil {
-		opts |= flagVerbose
+		opts |= filterVerbose
 	}
 
 	var ret C.int